Lead shielding efficiency from the gamma background measurements in the salt cavern of the Polkowice-Sieroszowice copper mine.

The studies of lead shielding efficiency from the gamma background measurements were performed in the salt cavern of the copper mine - a site considered for an underground laboratory. Within the energy range of 50-2700 keV, the measured gamma-ray count rates normalized to the mass of the high-purity detectors germanium crystal are 5.93 and 6.

Gamma background measurements in the Boulby Underground Laboratory.

To determine background radiation levels that might influence experiments, we measured in situ gamma-ray emissions at ten locations in the Boulby Underground Laboratory. For gamma radiation in the energy range of 7-2,734 keV, the counts varied from 6.5 to 28 γ s.

Gamma background measurements in the Gran Sasso National Laboratory.

In situ gamma-ray measurements were taken at eight locations in the Gran Sasso National Laboratory (Italy). Count rates for gamma radiation within the energy range of 7-2,734 keV varied from 8 to 60 γ s. The arithmetic mean was 49 γ s for measurements taken without a collimator.

Gamma background measurements in the Laboratoire Souterrain de Modane.

In situ gamma-ray measurements were taken at six locations in the Modane Underground Laboratory. Count rates for gamma radiation within the energy range of 7-2734 keV varied from 15 to 108 γs. The arithmetic mean was 79 γs for measurements taken without a collimator.